Anonymous
Yes. We have seen it. You should question (and come down hard on) your pigging company on their choice of pigs and consider switching companies. Using Eveready? Have them make a presentation in front of your management as to how they intend to reduce the quantity of metal shavings. Increase your monitoring of their activities.
Online spalling and steam-air decoking are options, of course. My experience is with steam-air decoking and pigging. Steam-air decoking can be optimized such that it can be performed almost as short as it takes to pig a heater. As I recall, we were able to able to achieve as low as 60 hours oil-out to oil-in with steam-air decoking whereas pigging can be accomplished comfortably in a 48 hour time frame.